//Breit-Wigner function
Double_t fitFunc(Double_t* x, Double_t* par)
{
  Double_t arg1 = 14.0/22.0; // 2 over pi
  Double_t arg2 = par[1]*par[1]*par[2]*par[2]; //Gamma=par[1]  M=par[2]
  Double_t arg3 = ((x[0]*x[0]) - (par[2]*par[2]))*((x[0]*x[0]) - (par[2]*par[2]));
  Double_t arg4 = x[0]*x[0]*x[0]*x[0]*((par[1]*par[1])/(par[2]*par[2]));
  return par[0]*arg1*arg2/(arg3 + arg4);
}


void RootTutorial2_2022_answer(){

	//load file
	TFile *f = new TFile("zjet_rec.root", "read");

	//load tree
	TTree *t = (TTree*)f->Get("Tdata");

	//plot Z boson mass
	TH1F *h = new TH1F("h","h",100,60,140);


	TCanvas *c1 = new TCanvas("c1","c1",1000,1000);

	Double_t m;

	//assign to where the mass should be saved
	t->SetBranchAddress("m",&m);

	for(int i = 0; i<t->GetEntries();i++){
		t->GetEntry(i);
		h->Fill(m,1);
	}


  h->Draw();
  
  //h->Fit("gaus");
  TF1 *func = new TF1("fitFunc",fitFunc,60,140,3);
  func->SetParameter(0,1.0);
  func->SetParameter(2,5.0);
  func->SetParameter(1,95.0);

  h->Fit("fitFunc");
	




}